Conventionally, there has been known a technology in which infrared light is emitted to a face, reflected light of the emitted infrared light is detected to be outputted as an infrared light image, and face recognition is performed by use of the infrared light image.
In the above technology, power consumption due to emission of infrared light is not particularly taken into consideration. Thus, in a case where the above technology is applied to, for example, a hand-held information terminal that operates on a battery, there is room for improvement in terms of battery consumption used for emission of infrared light.
Therefore, an object of the present exemplary embodiments is to provide an information processing apparatus, an information processing system, a computer-readable non-transitory storage medium having stored therein the information processing program, and an information processing method, which are capable of reducing power consumption due to emission of infrared light and at the same time capable of maintaining convenience of face detection using infrared light.
In order to attain the above object, the following configuration examples are conceivable, for example.
One example of the configuration example is an information processing apparatus including an infrared light emitter capable of emitting infrared light and a camera capable of at least taking an infrared light image, the information processing apparatus configured to: control emission of the infrared light; repeatedly obtain an image taken by use of the camera; and repeatedly execute a face detection process based on the obtained image, wherein in the infrared light emission control, emission of the infrared light is stopped based on a result of the face detection process performed in the face detection, and emission of the infrared light is resumed after a lapse of a predetermined time period.
According to the above configuration example, while convenience by the face detection process is maintained, power consumption used in emission of the infrared light can be suppressed.
As another configuration example, in the infrared light emission control, stopping emission of the infrared light and resuming emission of the infrared light after a lapse of the predetermined time period may be repeated.
According to the above configuration example, while power consumption used in emission of the infrared light is further reduced, convenience by the face detection process can be maintained.
As another configuration example, in the infrared light emission control, emission of the infrared light may be stopped when face detection with the infrared light emitted has been failure, and emission of the infrared light may be resumed after a lapse of the predetermined time period. Further, in the infrared light emission control, emission of the infrared light may be stopped when the number of consecutive failures of the face detection has become greater than a predetermined number, and emission of the infrared light may be resumed after a lapse of the predetermined time period.
According to the above configuration example, efficient power consumption reduction can be realized.
As another configuration example, in the infrared light emission control, stopping emission of the infrared light when face detection with the infrared light emitted has been failure and resuming the emission after a lapse of the predetermined time period may be repeatedly executed, until the face detection succeeds, with the predetermined time period being gradually extended. Further, in the infrared light emission control, as a result of the predetermined time period being extended, when the predetermined time period has reached a predetermined value, the predetermined time period may not be extended any longer and stopping emission of the infrared light and resuming the emission after a lapse of the predetermined time period may be repeatedly executed.
According to the above configuration example, while power consumption is further reduced, convenience by quick face detection can be maintained.
As another configuration example, the information processing apparatus may be further configured to detect a motion of the information processing apparatus itself, and
in the infrared light emission control, while stopping emission of the infrared light and resuming the emission after a lapse of the predetermined time period are repeatedly executed, when an output value of the detected motion is greater than or equal to a predetermined threshold, emission of the infrared light may be resumed regardless whether the predetermined time period has elapsed.
According to the above configuration example, for example, in a dark place, when a state where the user is not using the information processing apparatus has changed to a state where the user is using the information processing apparatus, face detection can be quickly performed.
As another configuration example, the information processing apparatus may be a hand-held information processing apparatus, or may be an information processing apparatus operable on a battery.
According to the above configuration example, while power consumption is reduced, convenience of the information processing apparatus can be enhanced.
According to the present exemplary embodiments, while power consumption used in emission of the infrared light is reduced, convenience of the face detection process can be maintained.